When a memory cell in a semiconductor memory device is defective, the defective memory cell is replaced with a redundancy memory cell for increasing the manufacturing yield of the semiconductor memory device. Thus, the semiconductor memory device is fabricated with redundancy memory cells.
Such redundancy memory cells are desired to be tested for proper operation before replacing defective memory cells. In particular, at least one fuse unit in a redundancy memory cell access circuit used to replace a defective memory cell with a redundancy memory cell is desired to be tested for proper operation.